/**
 * Copyright (c) 2005-2012 springside.org.cn
 */
package com.jims.common.utils;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.StringEscapeUtils;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * 封装各种格式的编码解码工具类.
 * 1.Commons-Codec的 hex/base64 编码
 * 2.自制的base62 编码
 * 3.Commons-Lang的xml/html escape
 * 4.JDK提供的URLEncoder
 * @author calvin
 * @version 2013-01-15
 */
public class Encodes {

	private static final String DEFAULT_URL_ENCODING = "UTF-8";
	private static final char[] BASE62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".toCharArray();

	/**
	 * Hex编码.
	 */
	public static String encodeHex(byte[] input) {
		return new String(Hex.encodeHex(input));
	}

	/**
	 * Hex解码.
	 */
	public static byte[] decodeHex(String input) {
		try {
			return Hex.decodeHex(input.toCharArray());
		} catch (DecoderException e) {
			throw Exceptions.unchecked(e);
		}
	}

	/**
	 * Base64编码.
	 */
	public static String encodeBase64(byte[] input) {
		return new String(Base64.encodeBase64(input));
	}
	
	/**
	 * Base64编码.
	 */
	public static String encodeBase64(String input) {
		try {
			return new String(Base64.encodeBase64(input.getBytes(DEFAULT_URL_ENCODING)));
		} catch (UnsupportedEncodingException e) {
			return "";
		}
	}

//	/**
//	 * Base64编码, URL安全(将Base64中的URL非法字符'+'和'/'转为'-'和'_', 见RFC3548).
//	 */
//	public static String encodeUrlSafeBase64(byte[] input) {
//		return Base64.encodeBase64URLSafe(input);
//	}

	/**
	 * Base64解码.
	 */
	public static byte[] decodeBase64(String input) {
		return Base64.decodeBase64(input.getBytes());
	}
	
	/**
	 * Base64解码.
	 */
	public static String decodeBase64String(String input) {
		try {
			return new String(Base64.decodeBase64(input.getBytes()), DEFAULT_URL_ENCODING);
		} catch (UnsupportedEncodingException e) {
			return "";
		}
	}

	/**
	 * Base62编码。
	 */
	public static String encodeBase62(byte[] input) {
		char[] chars = new char[input.length];
		for (int i = 0; i < input.length; i++) {
			chars[i] = BASE62[((input[i] & 0xFF) % BASE62.length)];
		}
		return new String(chars);
	}

	/**
	 * Html 转码.
	 */
	public static String escapeHtml(String html) {
		return StringEscapeUtils.escapeHtml4(html);
	}

	/**
	 * Html 解码.
	 */
	public static String unescapeHtml(String htmlEscaped) {
		return StringEscapeUtils.unescapeHtml4(htmlEscaped);
	}

	/**
	 * Xml 转码.
	 */
	public static String escapeXml(String xml) {
		return StringEscapeUtils.escapeXml10(xml);
	}

	/**
	 * Xml 解码.
	 */
	public static String unescapeXml(String xmlEscaped) {
		return StringEscapeUtils.unescapeXml(xmlEscaped);
	}

	/**
	 * URL 编码, Encode默认为UTF-8. 
	 */
	public static String urlEncode(String part) {
		try {
			return URLEncoder.encode(part, DEFAULT_URL_ENCODING);
		} catch (UnsupportedEncodingException e) {
			throw Exceptions.unchecked(e);
		}
	}

	/**
	 * URL 解码, Encode默认为UTF-8. 
	 */
	public static String urlDecode(String part) {

		try {
			return URLDecoder.decode(part, DEFAULT_URL_ENCODING);
		} catch (UnsupportedEncodingException e) {
			throw Exceptions.unchecked(e);
		}
	}

	/**
	 * Html 解码.(emr病历文书)
	 * @param htmlEscaped
	 * @return
	 */
	public static String unescapeHtmlEmr(String htmlEscaped) {
		if(StringUtils.isNotEmpty(htmlEscaped)){
			String htmlStr = StringEscapeUtils.unescapeHtml4(htmlEscaped);
			String regEx_script="<script[^>]*?>[\\s\\S]*?<\\/script>"; //定义script的正则表达式
			String regEx_style="<style[^>]*?>[\\s\\S]*?<\\/style>"; //定义style的正则表达式
			String regEx_html="<[^>]+>"; //定义HTML标签的正则表达式

			Pattern pattern = Pattern.compile("<!--[\\w\\W\r\\n]*?-->");
			Matcher matcher = pattern.matcher(htmlStr);
			htmlStr=matcher.replaceAll(""); //过滤html标签

			Pattern p_script= Pattern.compile(regEx_script, Pattern.CASE_INSENSITIVE);
			Pattern p_style= Pattern.compile(regEx_style, Pattern.CASE_INSENSITIVE);
			Matcher m_style=p_style.matcher(htmlStr);
			htmlStr=m_style.replaceAll(""); //过滤style标签

			Pattern p_html= Pattern.compile(regEx_html, Pattern.CASE_INSENSITIVE);
			Matcher m_html=p_html.matcher(htmlStr);
			htmlStr=m_html.replaceAll(""); //过滤html标签
			htmlStr=htmlStr.replaceAll(" ", "");
			return htmlStr; //返回文本字符串
		}else{
			return "";
		}
	}


	//反编译字符串
	public static String unescape(String src) {
		StringBuffer tmp = new StringBuffer();
		if(StringUtils.isNotEmpty(src)){
			tmp.ensureCapacity(src.length());
			int lastPos = 0, pos = 0;
			char ch;
			while (lastPos < src.length()) {
				pos = src.indexOf("%", lastPos);
				if (pos == lastPos) {
					if (src.charAt(pos + 1) == 'u') {
						ch = (char) Integer.parseInt(src
                                .substring(pos + 2, pos + 6), 16);
						tmp.append(ch);
						lastPos = pos + 6;
					} else {
						ch = (char) Integer.parseInt(src
                                .substring(pos + 1, pos + 3), 16);
						tmp.append(ch);
						lastPos = pos + 3;
					}
				} else {
					if (pos == -1) {
						tmp.append(src.substring(lastPos));
						lastPos = src.length();
					} else {
						tmp.append(src.substring(lastPos, pos));
						lastPos = pos;
					}
				}
			}
		}
		return tmp.toString();
	}

}
